Various lighting systems exist comprising a plurality of lighting devices, each device comprising a respective light source. In such systems it may be desirable to manage the plurality of lighting devices remotely, e.g. so as to manage the devices centrally and/or in coordinated manner. For example the system may comprise sports lighting, lighting in an entertainment environment such as stage lighting, outdoor lighting for various purposes, or lighting in the office or home.
To this end, messaging protocols are known for managing a plurality of lighting devices from a suitable control module or the like. As well as potentially controlling the light sources (e.g. switching them on or off, dimming them, and/or coordinating their operation), another aspect of managing the lighting devices is the ability to collect technical information from them. Such information may for example comprise status information reflecting the operational status experienced by the devices “in the field”, or information on the nature or capabilities of the devices.
One such protocol is RDM (“Remote Device Management”) which may be implemented over a DMX512 network (“Digital Multiplexing using 512 pieces of information”). This is described in ANSI (American National Standards Institute) specification E1.20.
Using a traditional DMX-RDM system or the like, it is possible to remotely obtain status information such as logging information, error counts, lifetime and/or switch times from a lighting device. This requires one or more DMX-RDM commands to be sent on a per-lightsource basis, individually addressing each light source from which status information is desired. To get the status information of full installation requires commands to be sent to all of the light sources, one at a time. This is bandwidth-intensive and so interrupts the normal DMX flow, and can result in visible flickering of the light sources.